URL — The new history entry's URL is given by this parameter. Note that the browser won't attempt to load this URL after a call to pushState(), but it might attempt to load the URL later, for instance after the user restarts the browser. The new URL does not need to be absolute; if it's relative, it's resolved relative to the current URL. The new URL must be of the same origin as the current URL; otherwise, pushState() will throw an exception. This parameter is optional; if it isn't specified, it's set to the document's current URL.